/*
* JFFS2 -- Journalling Flash File System, Version 2.
*
* Copyright (C) 2001-2003 Red Hat, Inc.
*
* Created by David Woodhouse <dwmw2@infradead.org>
*
* For licensing information, see the file 'LICENCE' in this directory.
*
* $Id: scan.c,v 1.121 2005/07/20 15:32:28 dedekind Exp $
*
*/
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/mtd/mtd.h>
#include <linux/pagemap.h>
#include <linux/crc32.h>
#include <linux/compiler.h>
#include "nodelist.h"
#include "mtd_nor.h"
#include "los_typedef.h"

#define DEFAULT_EMPTY_SCAN_SIZE 1024

#define DIRTY_SPACE(x) do { typeof(x) _x = (x); \
		c->free_size -= _x; c->dirty_size += _x; \
		jeb->free_size -= _x ; jeb->dirty_size += _x; \
        		}while(0)
#define USED_SPACE(x) do { typeof(x) _x = (x); \
		c->free_size -= _x; c->used_size += _x; \
		jeb->free_size -= _x ; jeb->used_size += _x; \
        		}while(0)
#define UNCHECKED_SPACE(x) do { typeof(x) _x = (x); \
		c->free_size -= _x; c->unchecked_size += _x; \
		jeb->free_size -= _x ; jeb->unchecked_size += _x; \
        		}while(0)

#define noisy_printk(noise, args...) do { \
	if (*(noise)) { \
		printk(KERN_NOTICE args); \
		 (*(noise))--; \
		 if (!(*(noise))) { \
			 printk(KERN_NOTICE "Further such events for this erase block will not be printed1\n"); \
         		 } \
    	} \
} while(0)

static uint32_t pseudo_random;

static int jffs2_scan_eraseblock(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
    unsigned char *buf, uint32_t buf_size);

/* These helper functions _must_ increase ofs and also do the dirty/used space accounting.
* Returning an error will abort the mount - bad checksums etc. should just mark the space
* as dirty.
*/
static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
struct jffs2_raw_inode *ri, uint32_t ofs);
static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
struct jffs2_raw_dirent *rd, uint32_t ofs);

#define BLK_STATE_ALLFF		0
#define BLK_STATE_CLEAN		1
#define BLK_STATE_PARTDIRTY	2
#define BLK_STATE_CLEANMARKER	3
#define BLK_STATE_ALLDIRTY	4
#define BLK_STATE_BADBLOCK	5

static inline int min_free(struct jffs2_sb_info *c)
{
    uint32_t min = 2 * sizeof(struct jffs2_raw_inode);
#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
    if (!jffs2_can_mark_obsolete(c) && min < c->wbuf_pagesize)
        return c->wbuf_pagesize;
#endif
    return min;

}

static inline uint32_t EMPTY_SCAN_SIZE(uint32_t sector_size) {
    if (sector_size < DEFAULT_EMPTY_SCAN_SIZE)
        return sector_size;
    else
        return DEFAULT_EMPTY_SCAN_SIZE;
}

int jffs2_scan_medium(struct jffs2_sb_info *c)
{
    int  ret;
    uint32_t i, empty_blocks = 0, bad_blocks = 0;
    unsigned char *flashbuf = NULL;
    uint32_t buf_size = 0;
    struct super_block *sb = (struct super_block *)NULL;
    struct os_mtd_nor_device *device = (struct os_mtd_nor_device *)NULL;
    if (!flashbuf) {
        /* For NAND it's quicker to read a whole eraseblock at a time,
        apparently */
        if (jffs2_cleanmarker_oob(c)) /*lint !e506*/
            buf_size = c->sector_size;
        else
            buf_size = PAGE_SIZE;

        /* Respect kmalloc limitations */
        if (buf_size > 128 * 1024)
            buf_size = 128 * 1024;

        D1(printk(KERN_DEBUG "Allocating readbuf of %d bytes\n", buf_size));
        flashbuf = kmalloc(buf_size, GFP_KERNEL);
        if (!flashbuf)
            return -ENOMEM;
    }
    sb = OFNI_BS_2SFFJ(c);
    device = (struct os_mtd_nor_device*)(sb->s_dev); /*lint !e413*/
    for (i = device->block_start; i<c->nr_blocks + device->block_start; i++) {
        struct jffs2_eraseblock *jeb = &c->blocks[i];
        ret = jffs2_scan_eraseblock(c, jeb, buf_size ? flashbuf : (flashbuf + jeb->offset), buf_size);
        if (ret < 0)
            goto out;

        jffs2_dbg_acct_paranoia_check_nolock(c, jeb);

        /* Now decide which list to put it on */
        switch (ret) {
        case BLK_STATE_ALLFF:
            /*
            * Empty block.   Since we can't be sure it
            * was entirely erased, we just queue it for erase
            * again.  It will be marked as such when the erase
            * is complete.  Meanwhile we still count it as empty
            * for later checks.
            */
            empty_blocks++;
            LOS_ListAdd(&c->erase_pending_list, &jeb->list);
            c->nr_erasing_blocks++;
            break;

        case BLK_STATE_CLEANMARKER:
            /* Only a CLEANMARKER node is valid */
            if (!jeb->dirty_size) {
                /* It's actually free */
                LOS_ListAdd(&c->free_list, &jeb->list);
                c->nr_free_blocks++;
			} else {
                /* Dirt */
                D1(printk(KERN_DEBUG "Adding all-dirty block at 0x%08x to erase_pending_list\n", jeb->offset));
                LOS_ListAdd(&c->erase_pending_list, &jeb->list);
                c->nr_erasing_blocks++;
            }
            break;

        case BLK_STATE_CLEAN:
            /* Full (or almost full) of clean data. Clean list */
            LOS_ListAdd(&c->clean_list, &jeb->list);
            break;

        case BLK_STATE_PARTDIRTY:
            /* Some data, but not full. Dirty list. */
            /* We want to remember the block with most free space
                and stick it in the 'nextblock' position to start writing to it. */
            if (jeb->free_size > (uint32_t)min_free(c) && (!c->nextblock || c->nextblock->free_size < jeb->free_size)) {
                    /* Better candidate for the next writes to go to */
                if (c->nextblock) {
                    c->nextblock->dirty_size += c->nextblock->free_size + c->nextblock->wasted_size;
                    c->dirty_size += c->nextblock->free_size + c->nextblock->wasted_size;
                    c->free_size -= c->nextblock->free_size;
                    c->wasted_size -= c->nextblock->wasted_size;
                    c->nextblock->free_size = c->nextblock->wasted_size = 0;
                    if (VERYDIRTY(c, c->nextblock->dirty_size)) {
                        LOS_ListAdd(&c->very_dirty_list, &c->nextblock->list);
                    } else {
                        LOS_ListAdd(&c->dirty_list, &c->nextblock->list);
                    }
                }
                c->nextblock = jeb;
            } else {
                jeb->dirty_size += jeb->free_size + jeb->wasted_size;
                c->dirty_size += jeb->free_size + jeb->wasted_size;
                c->free_size -= jeb->free_size;
                c->wasted_size -= jeb->wasted_size;
                jeb->free_size = jeb->wasted_size = 0;
                if (VERYDIRTY(c, jeb->dirty_size)) {
                    LOS_ListAdd(&c->very_dirty_list, &jeb->list);
                } else {
                    LOS_ListAdd(&c->dirty_list, &jeb->list);
                }
            }
			break;

        case BLK_STATE_ALLDIRTY:
            /* Nothing valid - not even a clean marker. Needs erasing. */
            /* For now we just put it on the erasing list. We'll start the erases later */
            D1(printk(KERN_NOTICE "JFFS2: Erase block at 0x%08x is not formatted. It will be erased\n", jeb->offset));
            LOS_ListAdd(&c->erase_pending_list, &jeb->list);
            c->nr_erasing_blocks++;
            break;

        case BLK_STATE_BADBLOCK:
            D1(printk(KERN_NOTICE "JFFS2: Block at 0x%08x is bad\n", jeb->offset));
            LOS_ListAdd(&c->bad_list, &jeb->list);
            c->bad_size += c->sector_size;
            c->free_size -= c->sector_size;
            bad_blocks++;
            break;
        default:
            printk(KERN_WARNING "jffs2_scan_medium(): unknown block state\n");
            BUG();
        }
    }

    /* Nextblock dirty is always seen as wasted, because we cannot recycle it now */
    if (c->nextblock && (c->nextblock->dirty_size)) {
        c->nextblock->wasted_size += c->nextblock->dirty_size;
        c->wasted_size += c->nextblock->dirty_size;
        c->dirty_size -= c->nextblock->dirty_size;
        c->nextblock->dirty_size = 0;
    }
#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
    if (!jffs2_can_mark_obsolete(c) && c->nextblock && (c->nextblock->free_size & (c->wbuf_pagesize - 1))) {
        /* If we're going to start writing into a block which already
        contains data, and the end of the data isn't page-aligned,
        skip a little and align it. */

        uint32_t skip = c->nextblock->free_size & (c->wbuf_pagesize - 1);

        D1(printk(KERN_DEBUG "jffs2_scan_medium(): Skipping %d bytes in nextblock to ensure page alignment\n",
            skip));
        c->nextblock->wasted_size += skip;
        c->wasted_size += skip;

        c->nextblock->free_size -= skip;
        c->free_size -= skip;
    }
#endif
    if (c->nr_erasing_blocks) {
        if (!c->used_size && ((c->nr_free_blocks + empty_blocks + bad_blocks) != c->nr_blocks || bad_blocks == c->nr_blocks)) {
            printk(KERN_NOTICE "Cowardly refusing to erase blocks on filesystem with no valid JFFS2 nodes\n");
            printk(KERN_NOTICE "empty_blocks %d, bad_blocks %d, c->nr_blocks %d\n", empty_blocks, bad_blocks, c->nr_blocks);
            ret = -EIO;
            goto out;
        }

        jffs2_erase_pending_trigger(c);
    }
    ret = 0;
out:
    kfree(flashbuf);
    return ret;
}

static int jffs2_fill_scan_buf(struct jffs2_sb_info *c, unsigned char *buf,
    uint32_t ofs, uint32_t len)
{
    int ret;
    size_t retlen;
    ret = jffs2_flash_read(c, ofs, len, &retlen, (char*)buf);
    if (ret) {
        D1(printk(KERN_WARNING "mtd->read(0x%x bytes from 0x%x) returned %d\n", len, ofs, ret));
        return ret;
    }
    if (retlen < len) {
        D1(printk(KERN_WARNING "Read at 0x%x gave only 0x%zx bytes\n", ofs, retlen));
        return -EIO;
    }
    D2(printk(KERN_DEBUG "Read 0x%x bytes from 0x%08x into buf\n", len, ofs));
    D2(printk(KERN_DEBUG "000: %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x\n",
        buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6], buf[7], buf[8], buf[9], buf[10], buf[11], buf[12], buf[13], buf[14], buf[15]));
    return 0;
}

static int jffs2_scan_eraseblock(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
    unsigned char *buf, uint32_t buf_size) {
    struct jffs2_unknown_node *node;
    struct jffs2_unknown_node crcnode;
    uint32_t ofs, prevofs;
    uint32_t hdr_crc, buf_ofs, buf_len;
    int err;
    int noise = 0;
#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
    int cleanmarkerfound = 0;
#endif

    ofs = jeb->offset;
    prevofs = jeb->offset - 1;

    D1(printk(KERN_DEBUG "jffs2_scan_eraseblock(): Scanning block at 0x%x\n", ofs));

#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
    if (jffs2_cleanmarker_oob(c)) {
        int ret = jffs2_check_nand_cleanmarker(c, jeb);
        D2(printk(KERN_NOTICE "jffs_check_nand_cleanmarker returned %d\n", ret));
        /* Even if it's not found, we still scan to see
        if the block is empty. We use this information
        to decide whether to erase it or not. */
        switch (ret) {
        case 0:		cleanmarkerfound = 1; break;
        case 1: 	break;
        case 2: 	return BLK_STATE_BADBLOCK;
        case 3:	return BLK_STATE_ALLDIRTY; /* Block has failed to erase min. once */
        default: 	return ret;
        }
    }
#endif
    buf_ofs = jeb->offset;

    if (!buf_size) {
        buf_len = c->sector_size;
	} else {
        buf_len = EMPTY_SCAN_SIZE(c->sector_size);

        err = jffs2_fill_scan_buf(c, buf, buf_ofs, buf_len);

        if (err)
        {
            return err;
        }
    }

    /* We temporarily use 'ofs' as a pointer into the buffer/jeb */
    ofs = 0;

    /* Scan only 4KiB of 0xFF before declaring it's empty */
    while (ofs < EMPTY_SCAN_SIZE(c->sector_size) && *(uint32_t *)(&buf[ofs]) == 0xFFFFFFFF)
        ofs += 4;

    if (ofs == EMPTY_SCAN_SIZE(c->sector_size)) {
#ifdef CONFIG_JFFS2_FS_WRITEBUFFER
        if (jffs2_cleanmarker_oob(c)) {
            /* scan oob, take care of cleanmarker */
            int ret = jffs2_check_oob_empty(c, jeb, cleanmarkerfound);
            D2(printk(KERN_NOTICE "jffs2_check_oob_empty returned %d\n", ret));
            switch (ret) {
            case 0:		return cleanmarkerfound ? BLK_STATE_CLEANMARKER : BLK_STATE_ALLFF;
            case 1: 	return BLK_STATE_ALLDIRTY;
            default: 	return ret;
            }
        }
#endif
        D1(printk(KERN_DEBUG "Block at 0x%08x is empty (erased)\n", jeb->offset));
        if (c->cleanmarker_size == 0)
            return BLK_STATE_CLEANMARKER;	/* don't bother with re-erase */
        else
            return BLK_STATE_ALLFF;	/* OK to erase if all blocks are like this */
    }
    if (ofs) {
        D1(printk(KERN_DEBUG "Free space at %08x ends at %08x\n", jeb->offset,
            jeb->offset + ofs));
        DIRTY_SPACE(ofs);
    }

    /* Now ofs is a complete physical flash offset as it always was... */
    ofs += jeb->offset;

    noise = 1;//10;

scan_more:

    while (ofs < jeb->offset + c->sector_size) {

        jffs2_dbg_acct_paranoia_check_nolock(c, jeb);

        cond_resched();

        if (ofs & 3) {
            printk(KERN_WARNING "Eep. ofs 0x%08x not word-aligned!\n", ofs);
            ofs = PAD(ofs);
            continue;
        }
        if (ofs == prevofs) {
            printk(KERN_WARNING "ofs 0x%08x has already been seen. Skipping\n", ofs);
            DIRTY_SPACE(4);
            ofs += 4;
            continue;
        }
        prevofs = ofs;

        if (jeb->offset + c->sector_size < ofs + sizeof(*node)) {
            D1(printk(KERN_DEBUG "Fewer than %zd bytes left to end of block. (%x+%x<%x+%zx) Not reading\n", sizeof(struct jffs2_unknown_node),
                jeb->offset, c->sector_size, ofs, sizeof(*node)));
            DIRTY_SPACE((jeb->offset + c->sector_size) - ofs);
            break;
        }

        if (buf_ofs + buf_len < ofs + sizeof(*node)) {
            buf_len = min_t(uint32_t, buf_size, (jeb->offset + c->sector_size - ofs));
            D1(printk(KERN_DEBUG "Fewer than %zd bytes (node header) left to end of buf. Reading 0x%x at 0x%08x\n",
                sizeof(struct jffs2_unknown_node), buf_len, ofs));
            err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
            if (err)
                return err;
            buf_ofs = ofs;
        }

        node = (struct jffs2_unknown_node *)&buf[ofs - buf_ofs];

        if (*(uint32_t *)(&buf[ofs - buf_ofs]) == 0xffffffff) {
            uint32_t inbuf_ofs;
            uint32_t empty_start;

            empty_start = ofs;
            ofs += 4;

            D1(printk(KERN_DEBUG "Found empty flash at 0x%08x\n", ofs));
        more_empty:
            inbuf_ofs = ofs - buf_ofs;
            while (inbuf_ofs < buf_len) {
                if (*(uint32_t *)(&buf[inbuf_ofs]) != 0xffffffff) { /*lint !e662 !e661*/
                    printk(KERN_WARNING "Empty flash at 0x%08x ends at 0x%08x\n",
                        empty_start, ofs);
                    DIRTY_SPACE(ofs - empty_start);
                    goto scan_more;
                }

                inbuf_ofs += 4;
                ofs += 4;
            }
            /* Ran off end. */
            D1(printk(KERN_DEBUG "Empty flash to end of buffer at 0x%08x\n", ofs));

            /* If we're only checking the beginning of a block with a cleanmarker,
            bail now */
            if (buf_ofs == jeb->offset && jeb->used_size == PAD(c->cleanmarker_size) &&
                c->cleanmarker_size && !jeb->dirty_size && !jeb->first_node->next_phys) {
                D1(printk(KERN_DEBUG "%d bytes at start of block seems clean... assuming all clean\n", EMPTY_SCAN_SIZE(c->sector_size)));
                return BLK_STATE_CLEANMARKER;
            }

            /* See how much more there is to read in this eraseblock... */
            buf_len = min_t(uint32_t, buf_size, (jeb->offset + c->sector_size - ofs));
            if (!buf_len) {
                /* No more to read. Break out of main loop without marking
                this range of empty space as dirty (because it's not) */
                D1(printk(KERN_DEBUG "Empty flash at %08x runs to end of block. Treating as free_space\n",
                    empty_start));
                break;
            }
            D1(printk(KERN_DEBUG "Reading another 0x%x at 0x%08x\n", buf_len, ofs));
            err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
            if (err)
                return err;
            buf_ofs = ofs;
            goto more_empty;
        }

        if (ofs == jeb->offset && je16_to_cpu(node->magic) == KSAMTIB_CIGAM_2SFFJ) {
            printk(KERN_WARNING "Magic bitmask is backwards at offset 0x%08x. Wrong endian filesystem?\n", ofs);
            DIRTY_SPACE(4);
            ofs += 4;
            continue;
        }
        if (je16_to_cpu(node->magic) == JFFS2_DIRTY_BITMASK) {
            D1(printk(KERN_DEBUG "Dirty bitmask at 0x%08x\n", ofs));
            DIRTY_SPACE(4);
            ofs += 4;
            continue;
        }
        if (je16_to_cpu(node->magic) == JFFS2_OLD_MAGIC_BITMASK) {
            printk(KERN_WARNING "Old JFFS2 bitmask found at 0x%08x\n", ofs);
            printk(KERN_WARNING "You cannot use older JFFS2 filesystems with newer kernels\n");
            DIRTY_SPACE(4);
            ofs += 4;
            continue;
        }
        if (je16_to_cpu(node->magic) != JFFS2_MAGIC_BITMASK) {
            /* OK. We're out of possibilities. Whinge and move on */
            noisy_printk(&noise, "jffs2_scan_eraseblock(): Magic bitmask 0x%04x not found at 0x%08x: 0x%04x instead\n",
                JFFS2_MAGIC_BITMASK, ofs,
                je16_to_cpu(node->magic));
            DIRTY_SPACE(4);
            ofs += 4;
            continue;
        }
        /* We seem to have a node of sorts. Check the CRC */
        crcnode.magic = node->magic;
        crcnode.nodetype = cpu_to_je16((je16_to_cpu(node->nodetype) | JFFS2_NODE_ACCURATE));
        crcnode.totlen = node->totlen;
        hdr_crc = crc32(0, &crcnode, sizeof(crcnode) - 4);

        if (hdr_crc != je32_to_cpu(node->hdr_crc)) {
            noisy_printk(&noise, "jffs2_scan_eraseblock(): Node at 0x%08x {0x%04x, 0x%04x, 0x%08x) has invalid CRC 0x%08x (calculated 0x%08x)\n",
                ofs, je16_to_cpu(node->magic),
                je16_to_cpu(node->nodetype),
                je32_to_cpu(node->totlen),
                je32_to_cpu(node->hdr_crc),
                hdr_crc);
            DIRTY_SPACE(4);
            ofs += 4;
            continue;
        }

        if (ofs + je32_to_cpu(node->totlen) >
            jeb->offset + c->sector_size) {
            /* Eep. Node goes over the end of the erase block. */
            printk(KERN_WARNING "Node at 0x%08x with length 0x%08x would run over the end of the erase block\n",
                ofs, je32_to_cpu(node->totlen));
            printk(KERN_WARNING "Perhaps the file system was created with the wrong erase size?\n");
            DIRTY_SPACE(4);
            ofs += 4;
            continue;
        }

        if (!(je16_to_cpu(node->nodetype) & JFFS2_NODE_ACCURATE)) {
            /* Wheee. This is an obsoleted node */
            D2(printk(KERN_DEBUG "Node at 0x%08x is obsolete. Skipping\n", ofs));
            DIRTY_SPACE(PAD(je32_to_cpu(node->totlen)));
            ofs += PAD(je32_to_cpu(node->totlen));
            continue;
        }

        switch (je16_to_cpu(node->nodetype)) {
        case JFFS2_NODETYPE_INODE:
            if (buf_ofs + buf_len < ofs + sizeof(struct jffs2_raw_inode)) {
                buf_len = min_t(uint32_t, buf_size, (jeb->offset + c->sector_size - ofs));
                D1(printk(KERN_DEBUG "Fewer than %zd bytes (inode node) left to end of buf. Reading 0x%x at 0x%08x\n",
                    sizeof(struct jffs2_raw_inode), buf_len, ofs));
                err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
                if (err)
                    return err;
                buf_ofs = ofs;
                node = (void *)buf;
            }
            err = jffs2_scan_inode_node(c, jeb, (void *)node, ofs);
            if (err) return err;
            ofs += PAD(je32_to_cpu(node->totlen));
            break;

        case JFFS2_NODETYPE_DIRENT:
            if (buf_ofs + buf_len < ofs + je32_to_cpu(node->totlen)) {
                buf_len = min_t(uint32_t, buf_size, (jeb->offset + c->sector_size - ofs));
                D1(printk(KERN_DEBUG "Fewer than %d bytes (dirent node) left to end of buf. Reading 0x%x at 0x%08x\n",
                    je32_to_cpu(node->totlen), buf_len, ofs));
                err = jffs2_fill_scan_buf(c, buf, ofs, buf_len);
                if (err)
                    return err;
                buf_ofs = ofs;
                node = (void *)buf;
            }
            err = jffs2_scan_dirent_node(c, jeb, (void *)node, ofs);
            if (err) return err;
            ofs += PAD(je32_to_cpu(node->totlen));
            break;

        case JFFS2_NODETYPE_CLEANMARKER:
            D1(printk(KERN_DEBUG "CLEANMARKER node found at 0x%08x\n", ofs));
            if (je32_to_cpu(node->totlen) != c->cleanmarker_size) {
                printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x has totlen 0x%x != normal 0x%x\n",
                    ofs, je32_to_cpu(node->totlen), c->cleanmarker_size);
                DIRTY_SPACE(PAD(sizeof(struct jffs2_unknown_node)));
                ofs += PAD(sizeof(struct jffs2_unknown_node));
			} else if (jeb->first_node) {
                printk(KERN_NOTICE "CLEANMARKER node found at 0x%08x, not first node in block (0x%08x)\n", ofs, jeb->offset);
                DIRTY_SPACE(PAD(sizeof(struct jffs2_unknown_node)));
                ofs += PAD(sizeof(struct jffs2_unknown_node));
			} else {
                struct jffs2_raw_node_ref *marker_ref = jffs2_alloc_raw_node_ref();
                if (!marker_ref) {
                    printk(KERN_NOTICE "Failed to allocate node ref for clean marker\n");
                    return -ENOMEM;
                }
                marker_ref->next_in_ino = NULL;
                marker_ref->next_phys = NULL;
                marker_ref->flash_offset = ofs | REF_NORMAL;
                marker_ref->__totlen = c->cleanmarker_size;
                jeb->first_node = jeb->last_node = marker_ref;

                USED_SPACE(PAD(c->cleanmarker_size));
                ofs += PAD(c->cleanmarker_size);
            }
            break;

        case JFFS2_NODETYPE_PADDING:
            DIRTY_SPACE(PAD(je32_to_cpu(node->totlen)));
            ofs += PAD(je32_to_cpu(node->totlen));
            break;

        default:
            switch (je16_to_cpu(node->nodetype) & JFFS2_COMPAT_MASK) {
            case JFFS2_FEATURE_ROCOMPAT:
                printk(KERN_NOTICE "Read-only compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs);
                c->flags |= JFFS2_SB_FLAG_RO;
                if (!(jffs2_is_readonly(c))) /*lint !e506*/
                    return -EROFS;
                DIRTY_SPACE(PAD(je32_to_cpu(node->totlen)));
                ofs += PAD(je32_to_cpu(node->totlen));
                break;

            case JFFS2_FEATURE_INCOMPAT:
                printk(KERN_NOTICE "Incompatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs);
                return -EINVAL;

            case JFFS2_FEATURE_RWCOMPAT_DELETE:
                D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs));
                DIRTY_SPACE(PAD(je32_to_cpu(node->totlen)));
                ofs += PAD(je32_to_cpu(node->totlen));
                break;

            case JFFS2_FEATURE_RWCOMPAT_COPY:
                D1(printk(KERN_NOTICE "Unknown but compatible feature node (0x%04x) found at offset 0x%08x\n", je16_to_cpu(node->nodetype), ofs));
                USED_SPACE(PAD(je32_to_cpu(node->totlen)));
                ofs += PAD(je32_to_cpu(node->totlen));
                break;
            }
        }
    }

    D1(printk(KERN_DEBUG "Block at 0x%08x: free 0x%08x, dirty 0x%08x, unchecked 0x%08x, used 0x%08x\n", jeb->offset,
        jeb->free_size, jeb->dirty_size, jeb->unchecked_size, jeb->used_size));

    /* mark_node_obsolete can add to wasted !! */
    if (jeb->wasted_size) {
        jeb->dirty_size += jeb->wasted_size;
        c->dirty_size += jeb->wasted_size;
        c->wasted_size -= jeb->wasted_size;
        jeb->wasted_size = 0;
    }

    if ((jeb->used_size + jeb->unchecked_size) == PAD(c->cleanmarker_size) && !jeb->dirty_size
        && (!jeb->first_node || !jeb->first_node->next_phys))
        return BLK_STATE_CLEANMARKER;

    /* move blocks with max 4 byte dirty space to cleanlist */
    else if (!ISDIRTY(c->sector_size - (jeb->used_size + jeb->unchecked_size))) {
        c->dirty_size -= jeb->dirty_size;
        c->wasted_size += jeb->dirty_size;
        jeb->wasted_size += jeb->dirty_size;
        jeb->dirty_size = 0;
        return BLK_STATE_CLEAN;
	} else if (jeb->used_size || jeb->unchecked_size)
        return BLK_STATE_PARTDIRTY;
    else
        return BLK_STATE_ALLDIRTY;
}

static struct jffs2_inode_cache *jffs2_scan_make_ino_cache(struct jffs2_sb_info *c, uint32_t ino)
{
    struct jffs2_inode_cache *ic;

    ic = jffs2_get_ino_cache(c, ino);
    if (ic)
        return ic;

    if (ino > c->highest_ino)
        c->highest_ino = ino;

    ic = jffs2_alloc_inode_cache();
    if (!ic) {
        printk(KERN_NOTICE "jffs2_scan_make_inode_cache(): allocation of inode cache failed\n");
        return NULL;
    }
    (void)memset_s(ic, sizeof(*ic), 0, sizeof(*ic));

    ic->ino = ino;
    ic->nodes = (void *)ic;
    jffs2_add_ino_cache(c, ic);
    if (ino == 1)
        ic->nlink = 1;
    return ic;
}

static int jffs2_scan_inode_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
struct jffs2_raw_inode *ri, uint32_t ofs)
{
    struct jffs2_raw_node_ref *raw;
    struct jffs2_inode_cache *ic;
    uint32_t ino = je32_to_cpu(ri->ino);

    D1(printk(KERN_DEBUG "jffs2_scan_inode_node(): Node at 0x%08x\n", ofs));

    /* We do very little here now. Just check the ino# to which we should attribute
    this node; we can do all the CRC checking etc. later. There's a tradeoff here --
    we used to scan the flash once only, reading everything we want from it into
    memory, then building all our in-core data structures and freeing the extra
    information. Now we allow the first part of the mount to complete a lot quicker,
    but we have to go _back_ to the flash in order to finish the CRC checking, etc.
    Which means that the _full_ amount of time to get to proper write mode with GC
    operational may actually be _longer_ than before. Sucks to be me. */

    raw = jffs2_alloc_raw_node_ref();
    if (!raw) {
        printk(KERN_NOTICE "jffs2_scan_inode_node(): allocation of node reference failed\n");
        return -ENOMEM;
    }

    ic = jffs2_get_ino_cache(c, ino);
    if (!ic) {
        /* Inocache get failed. Either we read a bogus ino# or it's just genuinely the
        first node we found for this inode. Do a CRC check to protect against the former
        case */
        uint32_t crc = crc32(0, ri, sizeof(*ri) - 8);

        if (crc != je32_to_cpu(ri->node_crc)) {
            printk(KERN_NOTICE "jffs2_scan_inode_node(): CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
                ofs, je32_to_cpu(ri->node_crc), crc);
            /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */
            DIRTY_SPACE(PAD(je32_to_cpu(ri->totlen)));
            jffs2_free_raw_node_ref(raw);
            return 0;
        }
        ic = jffs2_scan_make_ino_cache(c, ino);
        if (!ic) {
            jffs2_free_raw_node_ref(raw);
            return -ENOMEM;
        }
    }

    /* Wheee. It worked */

    raw->flash_offset = ofs | REF_UNCHECKED;
    raw->__totlen = PAD(je32_to_cpu(ri->totlen));
    raw->next_phys = NULL;
    raw->next_in_ino = ic->nodes;

    ic->nodes = raw;
    if (!jeb->first_node)
        jeb->first_node = raw;
    if (jeb->last_node)
        jeb->last_node->next_phys = raw;
    jeb->last_node = raw;

    D1(printk(KERN_DEBUG "Node is ino #%u, version %d. Range 0x%x-0x%x\n",
        je32_to_cpu(ri->ino), je32_to_cpu(ri->version),
        je32_to_cpu(ri->offset),
        je32_to_cpu(ri->offset) + je32_to_cpu(ri->dsize)));

    pseudo_random += je32_to_cpu(ri->version);

    UNCHECKED_SPACE(PAD(je32_to_cpu(ri->totlen)));
    return 0;
}

static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb,
struct jffs2_raw_dirent *rd, uint32_t ofs)
{
    struct jffs2_raw_node_ref *raw;
    struct jffs2_full_dirent *fd;
    struct jffs2_inode_cache *ic;
    uint32_t crc;

    D1(printk(KERN_DEBUG "jffs2_scan_dirent_node(): Node at 0x%08x\n", ofs));

    /* We don't get here unless the node is still valid, so we don't have to
    mask in the ACCURATE bit any more. */
    crc = crc32(0, rd, sizeof(*rd) - 8);

    if (crc != je32_to_cpu(rd->node_crc)) {
        printk(KERN_NOTICE "jffs2_scan_dirent_node(): Node CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
            ofs, je32_to_cpu(rd->node_crc), crc);
        /* We believe totlen because the CRC on the node _header_ was OK, just the node itself failed. */
        DIRTY_SPACE(PAD(je32_to_cpu(rd->totlen)));
        return 0;
    }

    pseudo_random += je32_to_cpu(rd->version);

    fd = jffs2_alloc_full_dirent(rd->nsize + 1);
    if (!fd) {
        return -ENOMEM;
    }
    (void)memcpy_s(&fd->name[0], rd->nsize + 1, rd->name, rd->nsize);
    fd->name[rd->nsize] = 0;

    crc = crc32(0, fd->name, rd->nsize);
    if (crc != je32_to_cpu(rd->name_crc)) {
        printk(KERN_NOTICE "jffs2_scan_dirent_node(): Name CRC failed on node at 0x%08x: Read 0x%08x, calculated 0x%08x\n",
            ofs, je32_to_cpu(rd->name_crc), crc);
        D1(printk(KERN_NOTICE "Name for which CRC failed is (now) '%s', ino #%d\n", fd->name, je32_to_cpu(rd->ino)));
        jffs2_free_full_dirent(fd);
        /* FIXME: Why do we believe totlen? */
        /* We believe totlen because the CRC on the node _header_ was OK, just the name failed. */
        DIRTY_SPACE(PAD(je32_to_cpu(rd->totlen)));
        return 0;
    }
    raw = jffs2_alloc_raw_node_ref();
    if (!raw) {
        jffs2_free_full_dirent(fd);
        printk(KERN_NOTICE "jffs2_scan_dirent_node(): allocation of node reference failed\n");
        return -ENOMEM;
    }
    ic = jffs2_scan_make_ino_cache(c, je32_to_cpu(rd->pino));
    if (!ic) {
        jffs2_free_full_dirent(fd);
        jffs2_free_raw_node_ref(raw);
        return -ENOMEM;
    }

    raw->__totlen = PAD(je32_to_cpu(rd->totlen));
    raw->flash_offset = ofs | REF_PRISTINE;
    raw->next_phys = NULL;
    raw->next_in_ino = ic->nodes;
    ic->nodes = raw;
    if (!jeb->first_node)
        jeb->first_node = raw;
    if (jeb->last_node)
        jeb->last_node->next_phys = raw;
    jeb->last_node = raw;

    fd->raw = raw;
    fd->next = NULL;
    fd->version = je32_to_cpu(rd->version);
    fd->ino = je32_to_cpu(rd->ino);
    fd->nhash = full_name_hash(fd->name, rd->nsize);
    fd->type = rd->type;
    USED_SPACE(PAD(je32_to_cpu(rd->totlen)));
    jffs2_add_fd_to_list(c, fd, &ic->scan_dents);

    return 0; /*lint !e429*/
}

static int count_list(LOS_DL_LIST *l)
{
    uint32_t count = 0;
    LOS_DL_LIST *tmp = (LOS_DL_LIST *)NULL;

    LOS_DL_LIST_FOR_EACH(tmp, l) {
        count++;
    }
    return count;
}

/* Note: This breaks if list_empty(head). I don't care. You
might, if you copy this code and use it elsewhere :) */
static void rotate_list(LOS_DL_LIST *head, uint32_t count)
{
    LOS_DL_LIST *n = head->pstNext;

    LOS_ListDelete(head);
    while (count--) {
        n = n->pstNext;
    }
    LOS_ListAdd(n, head);
}

void jffs2_rotate_lists(struct jffs2_sb_info *c)
{
    uint32_t x;
    uint32_t rotateby;

    x = count_list(&c->clean_list);
    if (x) {
        rotateby = pseudo_random % x;
        D1(printk(KERN_DEBUG "Rotating clean_list by %d\n", rotateby));

        rotate_list((&c->clean_list), rotateby);

        D1(printk(KERN_DEBUG "Erase block at front of clean_list is at %08x\n",
            LOS_DL_LIST_ENTRY(c->clean_list.pstNext, struct jffs2_eraseblock, list)->offset));
    }
    else {
        D1(printk(KERN_DEBUG "Not rotating empty clean_list\n"));
    }

    x = count_list(&c->very_dirty_list);
    if (x) {
        rotateby = pseudo_random % x;
        D1(printk(KERN_DEBUG "Rotating very_dirty_list by %d\n", rotateby));

        rotate_list((&c->very_dirty_list), rotateby);

        D1(printk(KERN_DEBUG "Erase block at front of very_dirty_list is at %08x\n",
            LOS_DL_LIST_ENTRY(c->very_dirty_list.pstNext, struct jffs2_eraseblock, list)->offset));
    }
    else {
        D1(printk(KERN_DEBUG "Not rotating empty very_dirty_list\n"));
    }

    x = count_list(&c->dirty_list);
    if (x) {
        rotateby = pseudo_random % x;
        D1(printk(KERN_DEBUG "Rotating dirty_list by %d\n", rotateby));

        rotate_list((&c->dirty_list), rotateby);

        D1(printk(KERN_DEBUG "Erase block at front of dirty_list is at %08x\n",
            LOS_DL_LIST_ENTRY(c->dirty_list.pstNext, struct jffs2_eraseblock, list)->offset));
    }
    else {
        D1(printk(KERN_DEBUG "Not rotating empty dirty_list\n"));
    }

    x = count_list(&c->erasable_list);
    if (x) {
        rotateby = pseudo_random % x;
        D1(printk(KERN_DEBUG "Rotating erasable_list by %d\n", rotateby));

        rotate_list((&c->erasable_list), rotateby);

        D1(printk(KERN_DEBUG "Erase block at front of erasable_list is at %08x\n",
            LOS_DL_LIST_ENTRY(c->erasable_list.pstNext, struct jffs2_eraseblock, list)->offset));
    }
    else {
        D1(printk(KERN_DEBUG "Not rotating empty erasable_list\n"));
    }

    if (c->nr_erasing_blocks) {
        rotateby = pseudo_random % c->nr_erasing_blocks;
        D1(printk(KERN_DEBUG "Rotating erase_pending_list by %d\n", rotateby));

        rotate_list((&c->erase_pending_list), rotateby);

        D1(printk(KERN_DEBUG "Erase block at front of erase_pending_list is at %08x\n",
            LOS_DL_LIST_ENTRY(c->erase_pending_list.pstNext, struct jffs2_eraseblock, list)->offset));
    }
    else {
        D1(printk(KERN_DEBUG "Not rotating empty erase_pending_list\n"));
    }

    if (c->nr_free_blocks) {
        rotateby = pseudo_random % c->nr_free_blocks;
        D1(printk(KERN_DEBUG "Rotating free_list by %d\n", rotateby));

        rotate_list((&c->free_list), rotateby);

        D1(printk(KERN_DEBUG "Erase block at front of free_list is at %08x\n",
            LOS_DL_LIST_ENTRY(c->free_list.pstNext, struct jffs2_eraseblock, list)->offset));
    }
    else {
        D1(printk(KERN_DEBUG "Not rotating empty free_list\n"));
    }
}

#ifdef typeof
#undef typeof
#endif